Project Summary: Maintenance of a non-human primate SPF breeding colony requires several factors to ensure the animals' physical and behavior health, breeding production, genetic diversity, and exclusion of specified pathogens. The pigtailed macaque, M. nemestrina, exhibits additional physical and behavioral characteristics that pose additional challenges in colony maintenance. M. nemestrina exhibit greater susceptibility to the pathogenic effects of many microorganisms. Their susceptibility to lentiviruses makes them valuable animal models for HIV/AIDS research.1-11 However, nonhuman primates in standard outdoor breeding colonies are exposed to environmental and vector-borne pathogens, such as Trypanosoma cruzi and Coccidioides immitis, and M. nemestrina demonstrate enhanced susceptibility to disease with such exposure. Care must also be taken to prevent M. nemestrina infants from hypothermia. In contrast to rhesus macaques (M. mulatta) which exhibit seasonal breeding, infant M. nemestrina are born year-round and must be maintained in a heated environment. Breeding management is also different between M. mulatta and M. nemestrina. M. mulatta can be bred in large multi-male, multi-female groups in large corrals with minimal infrastructure. In contrast, M. nemestrina form single male multi-female fission/fusion groups in the wild12,13 and attempts to form multi-male groups result in significant trauma. Even with stable, single-male breeding groups, productivity is lower for M. nemestrina than for M. mulatta.14 The Washington National Primate Research Center (WaNPRC) has over 50 years of breeding experience with this species,15 and has the expertise and resources to meet these challenges. With support from this U42 cooperative agreement, we will ensure the health of the SPF M. nemestrina colony, including maintaining the animals free of B virus, SIV, SRV, and STLV, along with control of environmental organisms, such as T. cruzi and C. immitis. Using appropriate bioinformatics tools, we will increase production of SPF M. nemestrina to meet the needs of HIV/AIDS investigators in a cost-effective manner. We will provide SPF M. nemestrina to investigators in accordance with NIH-directed priorities. We will expand pre-assignment screening of animals for T. cruzi, flaviruses, CMV, and AAV.